JPH07119130A - Water cut-off material - Google Patents

Abstract

PURPOSE:To prevent a local and excessive distribution of water under the influence of water pressure after construction and eliminate excessive scattering of a water cut-off material of a water cut-off layer during manufacturing time or before the execution of work. CONSTITUTION:In a water cut-off material where water permeable sheet-made coating materials 3 are installed to both sides and a water cut off agent layer is interposed between the coating materials 3, the coating materials 3 consist of composite unwoven cloth which comprises a surface layer 1 where the density of fibers is coarse and the coefficient of water permeability ranges from 1X10<-3> to 5X10<-3>cm/sec and a rear layer where the density of fibers is dense and the coefficient of permeability ranges from 2X10<-4> to 9X10<-4>. In case when drastic water pressure is applied after construction, the portion of the rear layer 2 of the coating material 3 checks the passage of drastic water induced by the water pressure and the water which has passed through the front layer is diffused into fine fiber to fiber voids of the rear layer 2 and fed to a water cut-of agent layer 4 while penetrating gradually into one rear layer 2 during its passage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a stop constructed for the purpose of waterproofing a bottom of a pond or a river, an inclined surface, a revetment, etc., or blocking water or a waste in civil engineering such as construction of an underground structure. It concerns water materials.

[0002]

2. Description of the Related Art As a water blocking material conventionally used for the above applications, as described in U.S. Pat. No. 3,186,896, a plate-like sheet and a corrugated sheet which are arranged so as to face each other at regular intervals. Widely used is a structure in which so-called laminated corrugated cardboard is formed by connecting the sheets with each other and the voids formed between the plate-like sheet and the corrugated sheet are filled with bentonite (water blocking agent).

Further, the laminated corrugated cardboard-type water blocking material has an advantage that it is advantageous for forming a water blocking layer on a steep wall surface, but since the voids of the cardboard are filled with bentonite, it has a unit area. Since the weight of the hit becomes heavy and it breaks and breaks when it is made long, only one side length of about 50 cm can be manufactured. Therefore, when laying, small pieces are laid down and deployed, and a lot of time is spent for laying and labor costs increase.

Therefore, as shown in FIG. 3, a sheet of water blocking material is formed by joining bentonite between needle punched nonwoven fabrics to form a water blocking layer, and joining the front and back nonwoven fabrics in a sandwich shape by needle punching. Alternatively, there is provided a sheet-like waterproof material in which bentonite processed into a granular shape is adhered to the back surface of a water-impermeable sheet with an adhesive.

Then, these water-stopping materials are used for the bottom of ponds and rivers,
When laid on an inclined surface or revetment, bentonite swells and forms a gel when it comes into contact with water, which exerts a permanent waterproofing property, preventing water in ponds and rivers from penetrating underground and flowing out. Demonstrate the function to prevent.

[0006]

However, the conventional sheet-like waterproof material in which bentonite is sandwiched between the above-mentioned non-woven fabrics is a non-woven fabric in which the front and back covering materials are entangled by needle punching, and the fiber density is relatively high. Not only is it rough and has a high hydraulic conductivity, but also has large voids between fibers, and when water is poured after laying construction, water rapidly enters the large interfiber voids in the surface non-woven layer and reaches the waterproofing agent. The situation often occurs. In this way, when a large amount of water locally acts on the waterproofing agent before wetting in this way, a water flow groove is created in the waterproofing agent layer, causing unevenness in the thickness of the waterproofing layer, which reduces the water resistance of the waterproofing material. Will be invited.

In addition, in the conventional sandwich-type water stopping material described above, when a water stopping agent is interposed between needle punching nonwoven fabrics, needle punching processing is performed to join the nonwoven fabrics on the front and back sides, during transportation, or at the work site. When laying and constructing, bentonite easily passes through between the fibers that make up the non-woven fabric and scatters out of the non-woven fabric layer. It causes thickness unevenness, and a uniform water blocking layer cannot be obtained. In addition, if the bentonite is scattered outside the nonwoven fabric layer, the amount of the bentonite is wasted with respect to the filling amount, and the scattering of dust deteriorates the working environment.

On the other hand, the waterproof material in which bentonite is adhered to the water-impermeable sheet has a relatively low strength, and therefore there is a concern that the waterproof material will be broken if earth and sand are put into the compartment with a hydraulic excavator or the like during construction. However, if the water blocking material is damaged, the water blocking function will be impaired, so careful attention is required for the construction. In addition, random free spaces tend to remain in the bentonite layer during laying, and if there are free spaces, the bentonite layer will be in a water-filled state and the water-stopping function will be deteriorated.

The present invention provides a waterproof material in which the above-mentioned problems and inconveniences of conventional waterproof materials are remarkably improved.

[0010]

According to the present invention, a nonwoven fabric, which is a covering material for the front and back sides of a sheet-shaped waterproof material, is coated with a fiber density gradient to control the water permeability of the coating material. By doing so, the above problem was solved. That is, the water-stopping material of the present invention, the coating material composed of a water-permeable sheet material is arranged on both sides,
In a water blocking material having a water blocking agent layer interposed between the coating materials, the coating material includes a surface layer having a coarse fiber density and a back layer having a dense fiber density, and the water permeability coefficient (cm / sec) of the surface layer. ) Is 1 × 10 ^{−3 to} 5 × 10 ⁻³ and the water permeability (cm /
sec) is 2 × 10 ^{−4 to} 9 × 10 ⁻⁴ .

The above coating materials having different water permeability on the front and back sides can be obtained by forming a layer having a smaller fineness and a higher fiber density on the back surface side than on the front surface side. For example, synthetic polymer fibers such as polyester, polypropylene, polyethylene, and polyamide, having a fineness of 2 to 15 denier, a fiber length of 50 to 90 mm, and a basis weight of 200 to 350 g / m ^2.
4 is formed by needle punching the fibrous web of FIG. 4 into a surface layer non-woven fabric, and using different components of thermoplastic synthetic polymers such as polyester, polypropylene, polyethylene, polyamide and ethylene vinyl acetate for the A component and the B component.
It has a fiber cross section as shown in and the fineness after division is 0.3-
0.7 denier, fiber length 38-76mm, weight 8
The splittable conjugate fiber web of 0 to 150 g / m ² is subjected to high-pressure water flow treatment to split the splittable conjugate fibers into ultrafine fibers and entangle each fiber to form a non-woven fabric. It can be obtained by arranging and needle punching both nonwoven fabrics and integrating them.

As another method, on the back surface of a fiber web having a fineness of 2 to 15 denier and a fiber length of 50 to 90 mm,
Fineness of 0.5-1.0 denier, fiber length of 50-90 m
It can also be obtained by arranging m of the fibrous web and needle punching to make the permeability gradient.

If the water permeability (cm / sec) of the non-woven fabric layer as the surface layer of the coating material is smaller than 1 × 10 ^-3 , the water permeability of the entire coating material deteriorates, and the gel of the water-stopping agent (bentonite) after the construction. It takes time to convert. Permeability coefficient (cm / s
When ec) is larger than 5 × 10 ⁻³ , the amount of water flowing to the back layer becomes excessive, and local excess water supply easily occurs in the bentonite layer.

If the water permeability coefficient (cm / sec) of the non-woven fabric layer, which is the back layer of the covering material, is smaller than 2 × 10 ^-4 , the water permeability of the whole covering material deteriorates remarkably, and a waterproofing agent (bentonite) after the construction. Cannot be gelled smoothly. Further, when the water permeability coefficient (cm / sec) is larger than 9 × 10 ⁻⁴ , a large amount of water is passed through the coating material, and a large amount of water reaches the bentonite layer in a short time to easily form grooves due to local water flow. . The water permeability of the backing layer nonwoven fabric is preferably 3 × 10 ^{−4 to} 6
It is × 10 ^-4 .

Then, two sheets of the above-mentioned coating material are used, and a non-woven fabric layer having a small water permeability is used as an inner surface to form a waterproofing agent layer between the coating materials. Thereafter, the laminate is subjected to needle punching. The water blocking material of the present invention is obtained by joining the front and back coating materials.

When the above waterproof material is insufficient in tensile strength during handling or construction, it is preferable to interpose a high-strength reinforcing sheet material. As the reinforcing sheet material, a woven fabric formed by arranging uniaxially stretched polypropylene film tape yarns in warp and weft is preferable in terms of strength and economy.

The waterproofing agent to be interposed between the coating materials is not particularly limited as long as it has an existing organic polymer or inorganic agent as a main component. For example, as the organic polymer, polyacrylic acid salts, polyvinyl alcohol, polyacrylonitrile, polyvinyl acetate or CMC can be used. As an inorganic waterstop,
For example, natural products or synthetic products of viscous minerals such as bentonite, paradenite, nontelonite, savonite, hectorite of the montmorillonite genus, attapulgite of the genus holmite, and sepirite can be used.

Further, the property of the water blocking agent is not particularly limited, and any of powder, granules, powder granules and the like can be applied. In addition, the water blocking agent fills and seals the water blocking agent between the coating materials, and the water blocking agent may have penetrated and dispersed inside the coating material from the viewpoint of the water blocking effect. Desirably, therefore, the particle size of the waterproofing agent is preferably 200 to 350 mesh (74 to 44 μm. With this waterproofing agent, about 3 to 8 m between the coating materials.
The water-stopping material formed by forming a m-thick layer can secure the desired water-stopping effect at the bottom of a pond or river.

[0019]

[Function] A covering material composed of a non-woven fabric of a surface layer having a large water permeability and a non-woven fabric of a back layer having a small water permeability, which is coated with a powdered water blocking agent, is used to prevent water entering the water blocking agent by water supply after construction. First, it smoothly passes through a rough surface layer having a high fiber density to reach the backing layer, but thereafter, in the backing layer having a high fiber density, the passage of water is restricted and penetrates into the backing layer. Therefore, water is gradually supplied from the back layer to the entire surface of the waterproofing agent, preventing the flow of the waterproofing agent due to a large amount of locally flowing water, and the earth pressure after laying,
A water blocking agent is gradually and uniformly swelled in a limited space pressed and sandwiched by water pressure to form a water blocking layer having a uniform thickness.

Further, the dense backing layer having a small fiber density and a low water permeability of the covering material suppresses excessive scattering of the waterproofing agent during manufacturing of the waterproofing material, transportation after manufacturing, construction work, etc. Prevent loss of waterproofing agent and prevent deterioration of work environment.

[0021]

EXAMPLE A card web made by mixing 70% of polyester fiber having a fineness of 8 denier and a fiber length of 51 mm with 30% of polyester fiber having a fineness of 3 denier and a fiber length of 51 mm is superposed and needle punched. As a result, a needle punched nonwoven fabric having a basis weight of 200 g / m ² and an apparent thickness of 2.5 mm was obtained. The fiber density of this non-woven fabric is 0.08 g / cm ³ , and the water permeability is 1.95 × 10.
It was ^-3 cm / sec.

On the other hand, a fiber having a fiber cross section as shown in FIG. 4 composed of a polyester component (A) and a polyamide component (B) was used.
After making a card web with a card machine using 6-division type composite fiber (3 denier, 51 mm), this web was formed into a high pressure columnar water stream (discharge water pressure 120 kg / cm ² , speed 3 m /
min) to make the above two components (A) and (B) into ultrafine fibers of 0.19 denier and entangle the fibers,
The non-woven fabric was 00 g / m ² and had an apparent thickness of 0.6 mm. The fiber density of this non-woven fabric was 0.17 g / cm ³ and the water permeability was 4.1 × 10 ⁻⁴ cm / sec.

Then, the needle punched nonwoven fabric and the water flow treated nonwoven fabric are overlaid and lightly needle punched, and as shown in FIG. 2, the surface layer (1) has a water permeability of 1.95 × 10 ^−3.
A nonwoven fabric having a fiber density of cm / sec and a backing layer (2) were used as a covering material (3) for a nonwoven fabric having a fiber density of 4.1 × 10 ⁻⁴ cm / sec and a dense fiber density.

Subsequently, the above-mentioned two covering materials (3) are respectively placed inside the dense backing layers (2) having the fiber density, and powdery bentonite (3 kg / m ² (3) is provided between the covering materials (3) and (3). Layer thickness of about 5 mm) to form a waterproofing agent layer (4), and a reinforced sheet material (5) woven by uniaxially stretched polypropylene film tape yarns laid on warp and weft. , Front and back coating
Needle punching (needle number 28 ^S ) is applied to the laminate of (3) (3), the reinforcing sheet material (5) and the waterproofing agent layer (4), and the front and back covering materials (3) and (3) are joined. Water stop material as shown in Figure 1 (6)
I said.

“Comparative Example” As shown in FIG. 3, a needle punched nonwoven fabric (11) (1) having a coarse fiber density of the above-mentioned example was prepared.
1) is used as the covering material for the front and back surfaces, and powdered bentonite is provided between the non-woven fabrics (11) and (11) in an amount of about 3 kg / m ^{2 as in the example.}
(Layer thickness of about 5 mm) is placed to form a waterproofing agent layer (41), and a uniaxially stretched polypropylene film tape yarn is laid on warp and weft to interpose a reinforcing sheet material (51). And needle punching (needle number 28
^S ) was applied to make a waterproofing material (61).

Table 1 shows the results of performance evaluation (waterproof pressure resistance) of the waterproof material of the example and the waterproof material of the comparative example.

[0027]

[Table 1]

The performance was evaluated according to JIS L-1079 in accordance with the water resistance test method, and a water pressure gauge for a water stop material and its auxiliary equipment were separately used.

Further, in Table 1, dry: bentonite is in a dry state (state before swelling by water absorption)
Water pressure resistance when water pressure is applied to the waterproof material. 30 min: After setting the water blocking material in the tester, contact it with water at a water pressure of 0.1 or less, and after 30 minutes of contact with water, apply water pressure to the water blocking material to obtain water resistance. Complete: The water pressure resistance when water pressure is applied in a state where bentonite is completely swollen by contacting with water after setting the waterproof material in the tester.

[0030]

As described in detail above, the water blocking material of the present invention (6)
Is a waterproof material in which a coating material (3) made of a water-permeable sheet material is arranged on both sides, and a waterproof agent layer (4) is interposed between the coating material (3). 3) consists of a surface layer (1) with a coarse fiber density and a back layer (2) with a high fiber density.
Permeability coefficient (cm / sec) is 1 × 10 ^{-3 to} 5 × 10 ^-3
Therefore, when water pressure is applied from the surface (1) side, water will
It passes through (1) relatively smoothly and reaches the back layer (2). However, the permeability coefficient (cm / sec) of the back layer (2) is 2 × 1.
Since it has a dense structure of 0 ^{-4 to} 9 × 10 ^-4 , after laying,
When abrupt water pressure is applied, as can be understood from Table 1, the coating material (3) blocks the abrupt passage of water due to the water pressure, and the water that has passed through the surface layer (1) is not covered by this back layer (2). It is dispersed in the fine inter-fiber voids and gradually penetrates the back layer (2) while passing through to reach the water blocking agent layer (4).

Therefore, water is gradually supplied from the backing layer (2) to the entire surface of the waterproofing agent layer (4), and a large amount of water is locally generated as in the conventional case, and a flow groove of the waterproofing agent is generated. It is possible to prevent such a phenomenon, and to gradually and gradually swell the waterproofing agent in a limited space pressed and sandwiched by earth pressure and water pressure after laying, thereby forming a waterproofing layer having a uniform thickness.

Further, due to the presence of the dense backing layer (2) having a low fiber permeability of the covering material (3), the waterproofing agent can be used at the time of manufacturing the waterproofing material, at the time of transportation after manufacturing, at the time of construction work, etc. It is possible to prevent excessive scattering of water and prevent loss of the waterproofing agent and deterioration of the working environment.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of a water blocking material of the present invention.

FIG. 2 is a cross-sectional view of a covering material in the water blocking material of the present invention.

FIG. 3 is a partially cutaway perspective view of a conventional water blocking material.

FIG. 4 is a cross-sectional view of a splittable conjugate fiber.

[Explanation of symbols]

 1. Surface layer with coarse fiber density 2. Backing layer with a dense fiber density 3. Coating material 4. Waterstop layer 5. Reinforcing sheet material 6. Water stop material

Claims (3)

[Claims] 1. A water-blocking material comprising a water-permeable sheet-like covering material on both sides, and a water-stopping agent layer interposed between the covering materials, wherein the covering material has a coarse fiber density surface layer. And a backing layer with a dense fiber density, and the water permeability coefficient (cm /
sec) is 1 × 10 ^{−3 to} 5 × 10 ⁻³ and the back layer has a water permeability coefficient (cm / sec) of 2 × 10 ^{−4 to} 9 × 10 ⁻⁴ . 2. The hydroentangled non-woven fabric according to claim 1, wherein the backing layer having a high fiber density of the covering material contains splittable conjugate fibers and is divided into fine pieces by splitting the splittable conjugate fibers by high-pressure water flow treatment. Water stop material. 3. The waterproof material according to claim 1, wherein a high-strength reinforcing sheet is interposed on the upper surface and / or the lower surface of the waterproof agent layer.